Tilt shift effect
Add blur to the top and bottom of the entire layer or object. Perfect to simulate a tiny world or a camera focus effect.

Blur controls how strong the blur is at the top and bottom, while Gradient blur sets how gradually the image transitions from sharp (in the middle) to blurry (towards the edges). A larger gradient blur gives a smoother, wider in-focus band.
Reference
All effects are listed in the effects reference page.